问题描述:

I have a 3d numpy array, eg:

`>>> A = np.arange(24).reshape(2,3,4)`

I want to take a 1d slice along axis 0 based on a pair of coordinates for axes 1 and 2:

`>>> h = 1`

>>> l = 2

>>> A[:,h,l]

array([ 6, 18])

So far so good. But what if my coordinate pair is stored as a tuple or a list, rather than two integers? I've experimented with a few obvious options, to no avail:

`>>> coords = (1,2)`

>>> A[coords]

array([20, 21, 22, 23])

>>> A[:,coords]

array([[[ 4, 5, 6, 7],

[ 8, 9, 10, 11]],

[[16, 17, 18, 19],

[20, 21, 22, 23]]])

>>> A[...,coords]

array([[[ 1, 2],

[ 5, 6],

[ 9, 10]],

[[13, 14],

[17, 18],

[21, 22]]])

I've googled around on this and not found anything, but it's entirely possible that I'm not searching with the appropriate jargon. So, apologies if this is an overly simplistic question!

You can construct the slice tuple directly, with something like:

```
In [11]: A[(slice(None),) + coords]
Out[11]: array([ 6, 18])
```

This is because calling `A[:, 1, 2]`

is equivalent / calls:

```
In [12]: A.__getitem__((slice(None, None, None), 1, 2))
Out[12]: array([ 6, 18])
```